Georgia Tech is probably better than Duke and Dartmouth as far as CS goes. Without Stamps, it would be a toss-up: you could go to any of them and not really regret it. But with Stamps, the return on investment at Georgia Tech is just far too high. You can use the money you save for grad school, or the down payment on a house, or anything you want, and the CS degree you get is no less valuable. If I had been lucky enough to get Stamps at GTech, I would definitely have committed there.
Also, from what I’ve heard from one of my friends who is currently attending with a Stamps Scholarship, the opportunities you get go beyond just the money. Better research/internship opportunities, dinners with important people, etc, etc. I think there are even 4 members of staff whose job is just to help out Stamps Scholars